This Filmtools Snap-On Deck for Filmtools Junior Carts is made of aluminum. The snap-on deck is an economical alternative to the larger and more expensive lower shelves. It was designed for Filmtools Junior Carts, so this will not fit on the Magliner Gemini Junior Carts unfortunately. This is due to the fact that Filmtools Junior Carts have mroe cross bars than what a Magliner has. This does a great job keeping smaller objects from sliding and/or falling through the frame.